simplify-ts

The multi-flavor TypeScript port of the "high-performance JavaScript 2D/3D polyline simplification" library Simplify.js - a combination of basic radial distance determination and the Douglas-Peucker algorithm.

Three different importable flavors:

1. Object-based point collections - Array<{x: number, y: number}>
2. Array-based point collections - Array<[number, number]>
3. LatLong-based point collections - Array<{latitude: number, longitude: number}>

Install

npm install --save simplify-ts

Compiled JavaScript and types are included with your NPM install. To run benchmarks, tests and custom builds, use git to clone the repository (then also run npm install in the cloned repository to get the required dependencies for development.)

git clone https://github.com/METACEO/simplify-ts.git

You will then find the benchmarks, src and test folders referenced in the package.json file.

Usage

Object-based point collections:

import {
    Simplify,
    ISimplifyObjectPoint
} from 'simplify-ts';

const points: ISimplifyObjectPoint[] = [ {x: 1, y: 2} /* ... */ ];
const tolerance: number = 0.5;
const highQuality: boolean = true;

const simplified_result = Simplify(points, tolerance, highQuality);

Array-based point collections:

import {
    SimplifyAP,
    ISimplifyArrayPoint
} from 'simplify-ts';

const points: ISimplifyArrayPoint[] = [ [1, 2] /* ... */ ];
const tolerance: number = 0.5;
const highQuality: boolean = true;

const simplified_result = SimplifyAP(points, tolerance, highQuality);

LatLong-based point collections:

import {
    SimplifyLL,
    ISimplifyLatLongPoint
} from './src';

const points: ISimplifyLatLongPoint[] = [ {latitude: 1, longitude: 2} /* ... */ ];
const tolerance: number = 0.5;
const highQuality: boolean = true;

const simplified_result = SimplifyLL(points, tolerance, highQuality);

Tests

Run npm test in the project's repository.

[jamesallen@dev simplify-ts]$ npm test

> [email protected] test /home/jamesallen/simplify-ts
> node test/test.js | faucet

✓ simplifies object-points correctly with the given tolerance
✓ simplifies object-points correctly with the given tolerance and high quality
✓ just return the object-points if it has only one point
✓ just return the object-points if it has no points
✓ simplifies array-points correctly with the given tolerance
✓ simplifies array-points correctly with the given tolerance and high quality
✓ just return the array-points if it has only one point
✓ just return the array-points if it has no points
✓ simplifies latlong-points correctly with the given tolerance
✓ simplifies latlong-points correctly with the given tolerance and high quality
✓ just return the latlong-points if it has only one point
✓ just return the object-points if it has no points
# tests 12
# pass  12
✓ ok

Benchmarks

Run npm run bench in the project's repository.

[jamesallen@dev simplify-ts]$ npm run bench

> [email protected] bench /home/jamesallen/simplify-ts
> node ./benchmarks/1k-objectPoints.js && node ./benchmarks/1k-arrayPoints.js && node ./benchmarks/1k-latlongPoints.js

Benchmarking simplify on 1118 object-points...
simplify (HQ) x 8,918 ops/sec ±0.42% (92 runs sampled)
simplify x 14,739 ops/sec ±0.52% (93 runs sampled)
Benchmarking simplify on 1118 array-points...
simplify (HQ) x 7,506 ops/sec ±0.47% (92 runs sampled)
simplify x 12,023 ops/sec ±0.55% (92 runs sampled)
Benchmarking simplify on 1118 latlong-points...
simplify (HQ) x 9,005 ops/sec ±0.53% (89 runs sampled)
simplify x 14,018 ops/sec ±0.55% (92 runs sampled)